1.
Peugeot - There isn't really a correct "English" way to say it. Properly, it's /
pé-OU-gué-OT/ (say it like it's French). Alot of English speakers say /pay-JO/ which isn't really right, but you can get away with saying it.
2.
Porsche - pronounced correctly as /PORSH-uh/
3.
KIEHL'S - pronounced as /KEELS/
4.
L'Oréal - typically pronounced as /loree-EL/ or /luh-oree-EL/. The first is most commonly used, the second isn't used as much, but is a closer translation of the French word. Both are accepted.
Actually, none of the words above are English words. Therefore, the "proper" way to pronounce them would be in their native dialect. What I gave you was the accepted English pronunciation of the words. Anyway, I hope that helped you a bit.